Virtually all consumers and industrial products, utilizing plastic molded components, have multiple components attached together with some form of snap fits. How to design snapfit joints for 3d printing 3d hubs. When commencing study of the classical elements, it is logical to begin with moldings. Snap fit latch design a snap fit latch is the simplest, quickest, and most costeffective method of assembling two or more parts. This chapter will give you a thumbnail sketch of the benefits of snapfits and the materials used to make them. Snap fit joints are classified according to their spring element and by separability of the joint. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. I got my snapmaker today, took me about 25 minutes to assemble and another 30 minutes to calibrate and start printing. Use of snapfit fasteners in the multilifecycle design.
See more ideas about sewing, sewing patterns and sewing clothes. Snapfit and diecast plastic model kits, balsa kits, vac. For a more indepth analysis of snap fit design and to dive deeper into the material properties, check out these guides below. The purpose here is to design a constantforce mechanism that can be applied to snap fit connectors to generate a constant f grm and f gim in an interference uncertainty range. Snap fit design snap fits are commonly used as an assembly method for injection molded parts. They facilitate easy and quick detachment of electrical components for repair. The specific name of the snap fit is usually named after the type of stress or strain it utilizes. Implement good design practices that reduce stress fillets, build direction and locating lugs and strain tapered profiles, cantilever width use a 0. Snap fit support flexibility is sometimes referred to as support stiffness. Classification of features into categories of locking features, locating features and enhancements of these is used as the basis for discussion.
Our designer of the month for february is maker club. Although they have been around for many years, they have recently become more important in an attempt to simplify assembly and its associated costs. If you continue browsing the site, you agree to the use of cookies on this website. The design factors to be kept in mind include the shape of the snap, the thickness. Cantilever snap designs are known to be the most common, and the u or l shape snaps are very popular as well.
The first snapfit handbook creating and managing attachments for plastic parts 2nd edition paul r. About the snap fit feature search autodesk knowledge. Below is simple table for designing snap fit joints from bayer snap fit joints for plastics a design guide, please consult the pdf for more info. Unlike most of the design reference book, this one gives design engineers very good logical ways, i. Overall, i found this to be the easiest 3d printer to assemble and use.
As i understand your joint is c cross section with 1st type. This is usually due to limited packaging space which can restrict the length of the snap. It will avoid the mistakes a young engineer might make, and the writer also provides several very good examples to guide experienced engineers creativity. One of the most common causes of snap fit failure is stress concentration at the sharp inside corner between the beam and wall to which it is attached. After a bit of research i learned that one way to do this is with snap fit joints.
Most all snap fit joint designs share the common design features of a protruding ledge and a snap foot. Snap fit design by neeraj kumar jha linkedin slideshare. The mechanics and optimization of cantilever snap joints. I have no mechanical engineering background so i didnt even know the relevant terminology. Snap fits work by using an undercut in one piece and, on the other, a lip or hook which snaps into the undercut. In general, the stiffness of the part to which the snap fit connects, isimportant. Combine 3d printed parts with snap fit design duration.
Snap fit features inventor autodesk knowledge network. This is the ideal time to consider using either an. An economical and reliable snap joint can also be achieved by rigid lugs on one side in combination with snap fitting hooks on the other fig. In the late 1980s, allied signal plastics published a snap fit design guide which documents the influence of support stiffness based on. The nonuniform distribution of lines fringes indicates a very uneven strain in the outer fibers. A cantilever snap fit latch basically consists of a protrusion some type of bead or hook at one end of the beam and a structural.
Master patterns within the kits fit any family member. Snap fit is used to fix two parts together in a certain position. The resulting sewing patterns will fit your unique body shape and dimensions. This design uses 17% more material and exhibits 46% higher strain than the optimal design. Pdf design guidelines for additive manufactured snapfit. While in the past injection molding has been the only viable method for producing snap fit joints in plastics, 3d printing opens up new opportunities and challenges in their design. Dsource snap fits assembly techniques for plastics d. A systematic approach to integral snapfit attachment design. This force reduction must be accounted for in the design calculations.
The program provides a workspace for the designer to test different scenarios by adjusting various input parameters and selecting different engineering materials for the snap fit design. Most snap fit joints have a common design of a protruding edge and a snapin area. The feature models the most common shapes for a snap fit. Design and analysis of snap fit joint in plastic part.
Snapfit latch design a snap fit latch is the simplest, quickest, and most costeffective method of assembling two or more parts. The first snap fit handbook creating and managing attachments for plastic parts 2nd edition paul r. Moldings are the smallest physical units the atoms, as it were of classical architecture, and so are easier to understand at first than the larger, more complex members formed from their combination. An economical and reliable snap joint can also be achieved by rigid lugs on one side in combination with snapfitting hooks on the other fig. Designing components with snap fits can save you time and money in production by reducing material costs and part quantities as well as improving ease of assembly.
Snap fit is formfitting joint which permits great design flexibility. Jones, short cantilever beam deflection analysis applied to thermoplastic snap fit design, 1987 spe. Seminar 1 presentation on snap fit design preparedby. No matter how you know him, jonathan rochelle is here to share a guide with the community on designing snaptogether models to optimize your 3d designs. Design guidelines for additive manufactured snapfit. How to design snap fit ball joints for 3d printing. Whether the snap joint is a cantilever or a cylindrical fit, they both function similarly. Snapfits are the simplest, quickest and most costeffective method of assembling two parts.
The four cantilevers on the control panel mod ule shown in fig. Snap fit assemblies also require more engineering calculations and analysis. You can design the joint to be either detachable, difficult to disassemble, or inseparable, depending on the dimension of the insert and the return angle. The flexure during snapping should not exceed the allowable strain limit of material. The tooling for the design in 4c is even simpler, because the designer can place the separation line of the tool along the edge of snap fit. The joints are generally stronger, but require greater assembly force than cantilevered joints. The snap fit design program is a webbased application that serves as an engineering tool in snap fit design. When designed properly, parts with snapfits can be assembled and disassembled numerous times without any adverse effect on the assembly. This design is particularly effective for joining two similar halves of a. A common joining mechanism among plastic parts is the snap fit. Each cad and any associated text, image or data is in no way sponsored by or affiliated with any company, organization or realworld item, product, or good it may purport to portray.
The design of the snap fit determines what it can be used for. You should also check for spherical joint clearance should be y2. Fundamentals of annular snapfit joints machine design. In this 30minute demo, well take a look at how cloudbased fea can help engineers design a better snap fit system. Design by analysis of a snap fit linking system between plastic parts. Occasionally a designer will not be able to design a cantilever snap fit configuration with a strain below the allowable limit of the intended material. This utilization of snap fit joints for plastic molded. The computeraided design cad files and all associated content posted to this website are created, uploaded, managed and owned by third party users. A product of the bayer design engineering services group, this manual is primarily intended as a reference source for part designers and molding engineers working with bayer thermoplastic resins.
With the 3in1 software, snapmakerjs, your stunning creation is just a few clicks away. The snap fit design depends on the expected use and life, and can hence vary substantially. It is based on a placement datum a point on a sketch or a 3d point, two directions, and a set of geometric parameters for determine the shape that can also be directly manipulated on the graphics. Press fits are normally used to obtain maximum pullout force. Snap fit provide both secure as well as easy assembly of the parts. This paper builds on relatively new methodologies and guidelines for arranging all attachment features on plastic parts comprising snap fit assembly. Snap fits are very useful because they eliminate screws, clips, adhesives, or other joining methods. How to design snap fit components fictiv hardware guide. The thickness of the optimal snap fit arm decreases linearly to 30% of the original crosssectional area. Torsion snap joint on a housing made of makrolon polycarbonate fig 6. A continuous annular snap joint offers a semihermetic seal and is better for single assembly applications a page 6 of 26 snapfit joints for plastics a design guide. Torsion snap fit joints annular snap fit joints this is a convenient form of joint for axissymmetrical parts. Contains the engineering formulas and worked examples showing how to design snap fit joints for bayer thermoplastic resins. Once the design is proven in testing and production, the backup lock can be eliminated.
249 375 212 810 176 1061 407 997 52 1218 230 612 183 639 706 156 1433 1232 312 1466 159 1502 844 1463 487 1191 1175 855 1167 1097 758 382 1172 313 43 969 803 994 661 986 808 133 422 1046